Well I was assuming that the person would of been smart enough to know that, I was also in a hurry this morning and didn't answer the question clearly. But you should never adjust the Air/Fuel mixture without the proper devices, and the spark plug advace is debatable, but the tuner manual tells you a little about tinkering with that to set your engine to a certain octane, so I wasn't 100% off, but for an unexperianced person, let a shop do that job to.